Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 80 insertions, 0 deletions

diff --git a/doc/rados/troubleshooting/cpu-profiling.rst b/doc/rados/troubleshooting/cpu-profiling.rst
new file mode 100644
index 000000000..b7fdd1d41
--- /dev/null
+++ b/doc/rados/troubleshooting/cpu-profiling.rst
@@ -0,0 +1,80 @@
+===============
+ CPU Profiling
+===============
+
+If you built Ceph from source and compiled Ceph for use with `oprofile`_
+you can profile Ceph's CPU usage. See `Installing Oprofile`_ for details.
+
+
+Initializing oprofile
+=====================
+
+``oprofile`` must be initalized the first time it is used. Locate the
+``vmlinux`` image that corresponds to the kernel you are running:
+
+.. prompt:: bash $
+
+   ls /boot
+   sudo opcontrol --init
+   sudo opcontrol --setup --vmlinux={path-to-image} --separate=library --callgraph=6
+
+
+Starting oprofile
+=================
+
+Run the following command to start ``oprofile``: 
+
+.. prompt:: bash $
+
+   opcontrol --start
+
+
+Stopping oprofile
+=================
+
+Run the following command to stop ``oprofile``: 
+
+.. prompt:: bash $
+
+   opcontrol --stop
+    
+    
+Retrieving oprofile Results
+===========================
+
+Run the following command to retrieve the top ``cmon`` results: 
+
+.. prompt:: bash $
+
+   opreport -gal ./cmon | less    
+    
+
+Run the following command to retrieve the top ``cmon`` results, with call
+graphs attached: 
+
+.. prompt:: bash $
+
+   opreport -cal ./cmon | less    
+    
+.. important:: After you have reviewed the results, reset ``oprofile`` before
+   running it again. The act of resetting ``oprofile`` removes data from the
+   session directory.
+
+
+Resetting oprofile
+==================
+
+Run the following command to reset ``oprofile``:  
+
+.. prompt:: bash $
+
+   sudo opcontrol --reset   
+   
+.. important:: Reset ``oprofile`` after analyzing data. This ensures that 
+   results from prior tests do not get mixed in with the results of the current
+   test. 
+
+.. _oprofile: http://oprofile.sourceforge.net/about/
+.. _Installing Oprofile: ../../../dev/cpu-profiler
+
+